Hiya, gotta add my own 2 cents to this.
First I'm not a huge fan of orbital strikes, feel they are a bit of a cop out. they cant be stopped, targeted or out manouvered.
Where as any other piece of artillery no matter how nasty does have the side effect of actually having to be on the battlefield,
therfore giving your opponent some actual chance of doing something about it.
As for giving double victory points, I dont think it would be an issue if the enemy were limited to say 1 or 2.
However if your opponent were cheesy enough(cough,cough) to take multiple per army card they could efectively limit the amount of vp's available to the nid player.
For example if 45 vp's were needed to win, the player could tailor a list to only give 42, or even 44 vp's. filling a good portion of his army cards with orbital strikes, using them if he had to and making sure they gave a good return on their vp cost.
Not that Im saying any1 would be so underhand, well ok mayb me sinse I thought of it. But even if I did cheat myself I could claim the actual victory plus the moral one for the army that lost. Ahhhhh